Navigator&#39;s instrument.



E. I. BOLJAHNJ NAVIGATOR'S INSTRUMENT. APPLICATION FILED SEPT. 28,1907.-

Patented Apr. 20, 1909.

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ATTORNEYS E. F. BOLJAHN. NAVIGATORS INSTRUMENT.

APPLICATION FILED SEPT.28,1907.

9l-8,947. Patented Apr. 20, 1909.

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NAVIGATOR$ INSTRUMENT.

APPLICATION FILED SEPT. 28, 1907 Patented Apr. 20,1909.

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4 INVENTOR Zrzzzfiflaj'aim,

% A TTORNEY8 WITNESSES rinrrnsn STATES PATENT enrich...

EMIL 1 BOLJAHN, or NEW YORK, N. Y.

NAVIGATORS IN STRUMEN T.

7 To all whom it may concern:

This invention relates to instruments for use by navigators for finding or locating a ships position on a chart with referance to an object or objects shown; and the object thereof is to provide an improved device or instrument of thisclass by means of which the position of a ship may be readily found by the bearing of one object on the chart, and the line of the ships intended track or by the bearing of two objects on the chart and the line of the ships intended track, or

a lineparallelthereto, or by thebearing of three objects on the chart and the line of the shi s intended track, or a line parallel to sair track, as previously projected on the chart. 7

The invention is fully disclosed in the following specification, of which the accompanying drawing forms a part, in which the separate parts of my improvement are desig nated by suitable reference characters in each of the views, and in which 2- 1 Figure 1 is a plan view of my improved navigators instrument. Fig. 2 a plan view of the base member of the instrument. Fig. 3 a partial plan view of a rotatable arm I which forms a part of the instrument, part of the construction being broken away. Fig. 4 a perspective view of the supplemental arm used in connection with the arm shown in Fig. 3. Fig. 5 a plan view of a center finder which forms a part of the instrument. Fig. 6 a section on the line 6, 6 of Fig. 1 and on an enlarged scale. Fig. 7 a section on the line 7, 7 of Fig. 6. Fig. 8 a section on the line 8, 8 of Fig. 6. Fig. 9 a section on the line 9, 9 of Fig. 1 and on anenlarged scale. Fig. 10 a section on the line 10, 10 of Fig. 1 an on an enlarged scale. Fig. 11 a modified form of the part shown in Fig. 5, and :Fig.

' 12 a diagrammatic view showing the instru- -ment in use.

In the practice of my invention I provide an annular base plate a, having a base extension (1 on which are formed bosses a,

said extension belng also provlded with a I Specification of Letters Patent.

tatable annular member Patented April 20, 1909.

Application filed september 28, 1907. Serial No. 394,968.

I bottom straight edge a and said base plate with inwardly directed arms of, which carry a central annular member a and the inner perimeterof said member is provided with an upwardly directed annular flange a 'l'he base plate a, also carries inwardly directed cardinal points a, the purpose of which will be hereinafter explained.

Mounted on the base plate a, and secured thereto by screws or other suitable fastening devices, are spaced ring members I) and 0, having inwardly and outwardly directed top flanges b and c and a base flange b and c and by the latter the rings are secured to the base plate a, as shown in Fig. 6. The upper face of. the inner ring member b, has a scale of degrees consisting of radially disposed lines or graduations engraved or stamped thereon, and on the outer face of the web or body portion are secured guide springs d. The inner ring member I) is further provided with radial arms b which carry a circular central member 7) corresponding to and overlying the circular central member a and resting .on and secured to the annular flange a thereof by screws 6 The outer ring member c has guide springs e secured on the inner face of the web or body portion thereof, and these springs are ada ted to bear against and guide a rotata le annular memberf, adapted to rotate between and be secured within the ring members b and c. On the up er face of the ro- I engrave, stamp or otherwise lace a scale f of degrees consisting of ra ially disposed lines or graduations, which in the construction shown, are equally spaced, alternate lines being numbered as indicated. To facilitate the manipulation of the rotatable annular member f indentations j are formed in the outer periphery of said annular member and a circumferential slot 0 is provided in the web or body portion of the ring 0, so that a pin or other instrument can be inserted through said slot 0 and into the indentations j to operate the memberf.

In carrying out my'invention I employ radial and rotatable arms or fingers g, 9 9 having circular heads g mounted on the annular flange a of the circular central member a and adapted to be firmly clamped or fixed to the ring members I) and c by screws g Two of these arms viz. g and g are similar in construction, and are of rolled steel or other suitable material, and are provided fixing or locking the arms at any desired near the outer ends thereof with yokes g which bridge the ring members 6 and c, and the rotatable annular member f and carry an extension g having a longitudinal-socket g formed therein. The vertical portions of the yokes .g have 0 positelydirected and horizontally disposed ocking lugs g which are adapted to underlie the flanges?) and c of the ring members Z) and 0 whereby the arms are prevented from beingraised from the chart and broken, and also co-act with the screw to create a binding action on the underside of the flanges b and e effectually point, and which will be readily understood by reference to Fig. 6.

When the chart in-use-is so large that the arms will not reach or cut-the object, the bearing of which has previously-been taken, itis necessary to'have alonger arm or finger. I accomplish this by supplying a supplemental extension arm or finger 7L, shown detached in Fig. 4 and attached in Fig. 3, and provided with a spring member hthaving a transverse inner end member if. When it is desiredto attach the extension arm orfinger hythe inner reduced'end 7L thereof is inserted'into'the socket g and the inner endlt of the spring member or arm h is slightly raised aboveand over the head of a screw or pin g connected with the yokes and allowed to snap down so i that a notch g h in the end ha of the spring member-71;. may engage the shank of the screw, or pin g behind the head thereof, thereby locking the extension arm or fingerh in place.

The arm or finger -g, is slightly different from the arms or fingers g and 9?, inthat the yoke g has a lateral extension in the opposite direction to that of theyokes carried by the arms or fingers g and g The line ofthe edges 00, ofthe several arms or fingers g, g and g are and must be absolutely true radially, that is, cut the exact center of the instrument, in order to insure a perfect finding.

A reader 2', is carried ona rotatable arm 7', and is adapted tobe swung over the edge a', of the arms orfingers and the scales so that the reading can be accurately ascertained.

In order to find or locate a ship without removing the instrument after marking with a pencil point the position on the chart, which is now necessary, I obviate the necessity of soiling the chart by marks, by employing a oenter'finder shown in Fig. 5, and comprising fine cross wires k carried by a circular member-'76 which is securedby screws or other suitable fastening devices in an annular groove (1 in: the underside ofthe circular central member a.

In order to hold or look the rotatable annular memberf at .a desiredpoint-I provide a screw Z, which passes downwardly through 2 in error eastly. north, correct magnetic, and applying this a top plate 111, similar in form to the part (1 and having a straight edge m directly over the rotatable annular member f and when desired. this screw is manipulated to bear on said member depressing it slightly against springs a, secured to the baseplate a, at

suitable distances as shown in Fig. 2, and these springs also serve to support the rotatable annular member f, spacing it from the base plate a, thereby reducing friction.

InFig. 11 I have shown a modification of the center finder shown in Fig. '5, provided with a central ring member 0, supported by the-cross wires 76*, this form will be used when a, mark is desired on the chart.

2111 the use of this instrument it is necessary to prepare beforehand the chart to be used, and 'a-line is made thereon indicating the course or direction it is desired to sail. The directionof'this line is ascertained by referring to the chart compass. re then apply the compass error; that is, for example, suppose the compass hasbeen found to he ()ur track line is due deviation 2 easterly makes this track line road N. 2 W. by our compass and we now rotate member], 2 to the right and lock it. The object of the rotatable ring is to make the instrument read as desired. in practice thisring is turned to the right or left so that the reading of the instrument will correspond withthe compass course as steered by the. ship, which course in turn should correspond .with the track line as marked on the chart. -It will be understood that after therrng f has been rotated and set in the desired position the arms 9, g and 5 are also set in the desired position according to the bearing of objects thathave-been.takenby the compass.

In cases where we desiretoloeato or lind the position of our ship on the chart-by means of one object in view, the position of which appears on the chart together with thepropose'd' track line of the ship we proceed as follows :We first get the conmass bearing of the object, and one of the arms is then set to the compass bearing of the object on thechart. We then place the instrument on the; chart with the center line thereo'l'in line with the track line on the chart. We then lay a parallelruler slightly extended adjacent: to the straight edges a and m and manipulate both the instrument and ruler untilthe arm in use cuts the object on the chart,the bearing of which has been tal zen. At-this time the center of the instrument where-the wires 7c cross'will be the ships place or position on the chart if the ship is on the track line, but if the shipisnot on the track line she will still be, in any case on the :line or extension of the line as shown by the In the use of thisinstrument in locating or finding the position oi; a ship on a chart when two objects are inview, the positions ships position which will be on the track line or on an imaginary line parallei thereto, and the ships position so found will be reliable. This method properly carried out is the most expeditious, convenient, and universally liked of all such methods now in use for finding or locating a ships position on a chart by the bearings of objects that are marked on the chart and is generally termed the cross bearing method. This method of operation is illustrated in Fig. 12 in which r represents the chart or a part thereof, and r and r two objects thereon, and r the proposed track line of the ship.

The third method of using this instrument for locating or finding the position oi a ship on a chart, when three objects are in view, the position of whichtogether with the track line of the ship are shown on the chart, is as follows:-This method involves two angles which are included by three lines represented by the three arms g, g and g of theinstrument which are set to the compass bearings oi the three objects on the chart. The crossing of these three lines will occur in the center or" the instrument which will be, or indicate, the ships position; After the arms have been set to the compass bearings of their respective objects, the instrument is placed on the chart and manipulated as before set out until the three arms out their respective -objects. This method is accurate, though not as convenient as the preceding one known as the cross-bearing method.

It will be understood that in each case, this instrument is placed so that the center line of the instrument corresponds to the vessels track line as previously marked on the chart, and then manipulated until the arms 1 cut their res ective obj ects' without sluing or twisting tile instrument in any way from the parallel of the track line. It is in this very respect that the expediency and usefulness of this instrument is superior to all other'position finding instrumentsof this class now in The instrument 1S previously set to the.

use. intended track lineand any compass error allowed for. Then allbcarings taken by the compass are so placed on the instrument without making further allowance for compass error as that has already been "allowed easily applied in the wrong way.

for in setting the instrument. It will also be seen that in this proceeding some time is gained and much worry saved, as the compass error may in a moment of hurry, be very This has often occurred, but in using this instrument the compass error is considered while setting the instrument to the intended course, which may, in most cases, he done beforehand, and this once done, there is no more worry about the compass error until the track line takes on a different direction.

When sailing along a track line it is by no means, necessary that the ship should be absolutely on the course, as long as the bearings of objects used for finding her position are taken by compass, as nothing but a difference of compass deviation could cause an error here, but if these hearings are taken by the pelorus or some other dummy instrument, it

ecomes of the utmost importance that the ship should be on her course while the bearin s are taken, or the ships position so found wi 1 be erroneous. This is self-evident to anyone having any knowledge of these facts. In using these instruments it is necessary to prepare the chart beforehand, and in doing this a chart is selected embracing the region you wish to traverse, a large scaled chart being selected. The proposed sailing line or track line of the ship is then marked on the chart, clear of all dangers or objects that must be avoided. i/Ve then ascertain the direction or this track line by referring to the chart com pass and then apply the deviation of the compass on this particular course and mark this whereon the chart and other navigating outfit is placed for use. When running near the shore etc., navigating in this way with parallel rulers and scores of pencil lines drawn on the chart is quite convenient in pleasant weather, but when it becomes wet or breezy this outfit will have to he placed under cover and as constant reference to the chart compass will have to be made this method with pencil and sliding parallel rulers ber omes somewhat less agreeable, besides it will soil the chart. Now inhaving the chart prepared with a track line you may place it under the glass cover so that this line as well as those objects whosebearings you use for finding the position are seen through the glass. The

A spaced rings, the inner spaced rii n'istruinent and the diree 'ioii of the trash line will familiarize him with the ships immediate surroundings and enable him to decide at once what to do.

The instrument is left in position until new objects become available for bearings, or the bearings of objects formerly taken have changed. In thi way perfect track of the ships movements is kept.

Having fully described my invention, what I claim as new and desire to secure by Let ters Patent is 1. In a navigators instrument, an annular base plate, an annular central me -iber eonsaid base plate, an annular scale member rotatably mounted between said spaced rings, and radial arms mounted on and adapted to be rotated on he central member and over the spaced rings and the annular member mounted between saidv rings.

2. In a navigators instrument, an annular base plate, a central annular member connected therewith, spaced rings concentrically mounted on said base plate, an annu ar member rotatably mounted between said spaced rings, the inner spaced rm and said annular rotatable member being provided with scales, and radial arms in our ed on and adapted to be rotated on the central mem ber ad over the spaced rings and annular member mounted bcwe i said rings.

3. in a navigators instrument, an annular base plate, central annular member connected therewith, spaced coneentrically mounted on said plate an annular member rotatably mounted b tween saidv 1g and said annular rotatable mnnbcr being provided with sales, and. radial are s mounted on and adapted to be rotated on the central member and over spaced rings and the annular member mounted between said rings, said base plate being also provided with cardinal points.

4. in a navigators inst 'ument, an annular base plate, and an amiular central member conneeted therewith, s; eed rings concentrically mounted on said base plate, an annular member rotatabl mounted between said spaced rings, the inner spaced ring and said rotatable annular member being, provided with scales, and four rotatable arms mounted on and adapt-ed to be rotated on the central member and over the spaced rings and the annular member mounted between said rings, three of said arms being provided with, means for locking them to the spaced rings.

5. in a navi .,ators instrument, an annular base plate, and an annular central member connected. herewith, spaced rings concentricall mounted on said base plate, an annular member rotatably mounted between said rings, the inner spaced ring and said rotatable annular member being provided with scales, and four rotatable arms mounted on and adapted to be rotated on the central member and over the spaced rings and the annular member connected between said rings, three of said arms being provided with means for locking them to the spaced rings, and the other arm with a reader.

6. In a navigators instrument, an annular base plate, and an annular central member connected therewith, spaced rings concentrically mounted on said base plate, an an nular member rotatably mounted between said spaced rings, the inner spaced ring and H said rotatable annular member being pronected therewith, spaced rings mounted on vided with scales, and four rotatable arms mounted on and adapted to be rotated on the central member and over the spaced rings and the annular member mounted between said rings, three oi said arms being provided with means for locking them to the spaced rings and the other arm with a reader, the first three fl-l'li'iS being also provided with detachable extensions.

7. in. a navigators instrument, an annular base plate, an annular central member connected therewith, spaced. rings mounted on said base plate, an annular member iotatably moiuited between said spaced rings, and radial arms mounted on and adapted to be re ated on the central member and over the spaced rings and the annular member mounted between said rings, said instrument being also provided at one side with a straight edge.

8. ln a navigatons instrument, an annular base plate, a central annular member connected therewith, spaced rings concentricall mounted on said base plate, an annular member rotatably mounted between said spaced rings, the inner spaced ring and. said annular rotatable member being provided with scales, and radial arms meunted on and adapted to be rotated on the eei'itral member and, over th= spaced rings and the annular member mounted between said rings, said instrument being also provided at one side with a straight edge.

9. In a navigatofls instrument, an annular base plate, and. an annular central member :onnecled therewith, spaced rings concentrically mounted on said base plate, an annular member rotatably mounted between said spaced rings, the inner spaced ring and said rotatable annular member being; pro vided with scales, and four rotatable arms mounted on and adapted to be rotated on the central member and over the spaced rings and the annular member mounted between said rings, three ofsaid arms being provided with means for lockingthem to the spaced rings, said-instrument being alsoprovided at one side with a straight edge. Y

10. In a navigators instrument, anannular base plate, an annular central member connected therewith, spaced rings mounted on said base plate, an annular scale member rotatably mounted; between said spaced.

rings, and radial arms mounted on and adapted to be rotated on the central mem center finder, consisting of a ring secured therein and radial cross wires connected therewith,

12. In a navigators instrument, an annular base plate, an annular central member connected therewith, spaced rings mounted on said base plate, an annular scale member rotatably mounted between said spaced rings, and radial arms mounted on and adapted to be rotated on the central member and over the spaced rings and the annular member mounted between sald rings, said central annular member being also provided with a center finger, consisting of a ring secured therein and radial cross wires connected therewith, said radial cross wires being connected with a central eye or ring.

13. In a navigators instrument, an annular base plate, a central annular member connected therewith and provided with an inner annular flange, spaced rings concentrically mounted on said base plate, an annular rotatable member mounted between said spaced rings, the inner spaced ring and the annular rotatable member being provided with scales,

said base plate being provided with cardinal points, and four radial arms rotatably mounted on said centralmember and adapted to be rotated over the base plate, three of said arms being provided with means for locking them to the spaced rings, and said instrument beingalso provided at one side with a straight edge. 7

14. In a navigators instrument, an annular base plate, a central annular member connected therewith and provided with an inner annular flange, spaced rings concentrically mounted on said base plate, an annular rotatable member mounted be spaced rings, the inner spaced ring anc annular rotatable member being provide l rotatably mounted on said central member and adapted to be rotated over plate, threeof said arms being provided with the base means for locking them to the spaced rings, and said instrument being also provided at one side with a straight edge, and one of said arms being provided with a reader.

15. Ina navigator s instrument, an annu- ;lar base plate, central annular member connected therewith and provided with an inner annular flange, spaced rings concentrically mounted on said base plate, an annular rotatable member mounted between said spaced rings, the inner spaced ring and the with scales, said base plate being provided with cardinal points, and four radial arms rotatably mounted on said central member andadapted to be rotated over the base plate, three of said arms being provided with means for locking them to the spaced rings, and said instrument being also provided at one side with a straight edge, and one of said arms being provided with a reader, and the first three arms being provided with detachable extensions.

16. In a navigators instrument, an annular base plate, an annular central member connected therewith, spaced rings mounted on said base plate, a rotatable annular member mounted between said spaced rings, radial arms mounted on and adapted to be rotated over the central member and over the base plate, and means for locking the ;o tatable annular member against rotation.

17. In a navigators instrument, an annular base plate, an annular central member connected therewith, spaced rings mounted on said base plate, a rotatable annular member mounted between said spaced rin s, radial arms mounted on and adapted to be rotated over the central member and over the base plate, and means for locking the retatable annular member against rotation, said instrument being also provided at one side with a straight edge.

18. A navigators instrument comprising a base member provided with an annular scale member, a rotatable scale member mounted in connection with the annular scale mem ber, a central annular member and radial arms rotatably mounted on the central annular member.

19, A navigators instrument comprising a base member provided with an annular scale member, a rotatable scale member mounted in connection with the annular scale mem ber,'a central annular member and radial arms rotatably mounted on the central annular member, three of said arms being pro- 04 with means for locking them to the annular scale member.

20. A navigators instrument comprising a base member provided With an annular scale member, a rotatable scale member mounted in connection With the annular scale memher, a central annular member and radial arms rotatably mounted on the central annular member, three of said arms being provided With means for locking them to the annular scale member, and the rotatable scale member being also provided With-a locking device.

21. A navigators instrument comprising a base provided with a stationary annular scale, a rotatable scale member mounted in connection therewith, a central circular open member, rotatable arms mounted on the central circular member, and extending over the base and stationary and rotatable scale, said. instrument being provided at one side with a straight edge.

In testimony that I claim the foregoing as my invention I have signed my name in presence of the subscribing witnesses this 2.3 rd day of September, 1907.

EMIL F. BOLJAUN. l/Vitnesses M. E. DooDY, C. E. lVlULREANY. 

